Looks like my E55 finally has the fuel tank leak issue. I normally fill the car up when I park it for an extended period of time so next time I take it out I got a full tank. Never smelled any fuel, the car started running rough whenever you gave it more than 1/4 throttle and the next day didn't want to start, just sat there cranking. Pulled the back seat off and checked the tops of the fuel tank, found that the passenger side electrical connector was filled with fuel and probably shorted out the relay and the fuse.

The replacement for the leaking plastic piece is $500+ but seems kind of silly to replace two working fuel pumps, a sending unit and a filter when everything is in working because some plastic is leaking. Has anybody successfully fixed the leak with a sealant? If so what kind is safe for fuel?

 

When was the last time the filter was changed....?????? IMO replace it.

 

Seeing that Mercedes doesn't offer a replacement part, its inside the driver side fuel sender, I would say never. Thought I would check it out, figuring I was working with brittle plastics I was very carefully undoing the fuel line when the plastic 90 degree elbow let go unceremoniously. Gonna have to order the fuel sender side as well.

Really a great job by Mercedes here, it's like they designed the fuel system to fail, lack of a replacement fuel filter is confirmation. It's obviously a cascading failure, fuel filter gets clogged, pump have to work harder and draw more current and end up burning out wires, connectors, relays and fuses. The burned out connectors melted the plastic housing causing a fuel leak from the top of the tank. Luckily my car didn't catch on fire, this was certainly a possibility as there was fuel and ignition source there.

I can't help and be disappointed by Mercedes engineering, this is on the level of negligence and these cars should have been recalled a long time ago.

 

OP, the E55 used cutting edge technology in its day 17 years ago and you're complaining it doesn't meet your expectations because failures are occurring almost two decades later? Deal with it. Who would have ever guessed plastics get brittle with age?

Face it, if you own an E55 AMG, expect to spend ~$1000 on the fuel system every 60,000 miles. If you can't accept that, sell the car and purchase whatever floats your boat. Tough love, bro. Embrace the suck or bail out of the game. I accepted the challenge and have multiple posts on how to address this issue with minimal (minimal, not no) pain. But it still costs $1000 every 60,000 miles.

FWIW, Creative Steel sells a replacement fuel filter for $55 but that does not address the advancing brittleness of the plastics in the car. You place your bets, you take your chances.

Quit complaining, repair your car, and get out and drive it and enjoy it!

 

My expectation of failure don't include the potential of the car catching fire due to the "cutting edge technology". There is nothing cutting edge in there, its just molded plastics, rubber lines, brushed electric motors and some floats, this system only exists for packaging reasons and lazy engineering. Replacing a simple fuel filter shouldn't be a $1000 affair, nor should you be risking/breaking $500 parts while doing basic maintenance because "plastic gets brittle". You're sounding like a BMW M5 owner who claims that replacing rod bearings is normal maintenance. Its obviously a terrible design, plenty of unhappy owners and NHTSA thought so and put pressure on Mercedes but instead of doing an actual recall Mercedes saved some money by extending the warranty. Don't worry about me, I will fix it, I will improve it, it won't cost me $1000 and Mercedes isn't going to get a dime from me for this repair.

Face it, you and I drive a car that one day will leave us stranded and may burn down because of cut corners not cutting edge technology.

 

Its not the best design but checking your fuel pressure regularly and changing your fuel filter as preventative maintenance will avoid both fire and leaving you stranded. Unfortunately most people coming into these cars in the last few years will have to deal with this expense often without prior knowledge (research).

 

https://www.ebay.com/itm/New-Genuine...QAAOSwjp9dcBUw
395.00 Next time you can just do the paper element

If you're able and willing to modify the old style pumps to the new sender, pumps can be had for 169.00
Since you only need the hat's, you could really cheap out and find some used ones on fleabay and then just change out the paper element.
You can always go aftermarket...
Good Luck in what ever you decide

 

JB Weld anything and everything

 

Unfortunately it is often through the electrical connector so won't help. I tried on mine, didn't work but is worth a go. You might get lucky if it is somewhere else on the top.

 

I recently had this issue on my 2005. I emailed Mercedes Canada and explained the issue. They fixed it for free. This was in August. Email Mercedes and see what they can do for you.

 

In the US, the fuel tank is covered for 15 years, unlimited miles. But a 2004 might be past the 15 year mark. But you never know, calling MB might get some discount on goodwill repair.

Also I think before the warranty kicked in a few years ago, some people mentioned fixing the leaking by just using some RTV sealant, probably have to search the regular W211 forum for it.

 

I get your point but checking fuel pressure as a part of regular maintenance is unheard of outside of race cars, so is saying "yes" when your dealer hands you a bill for $1500 to replace a fuel filter. Why they didn't offer a replacement filter is hard to tell, I guess they decided to defraud their customers by making them purchase a $500 part just to get a $5 filter.

The wiring is undersized for the potential sustained current draw by both pumps, the 30amp fuse is oversized for the circuit and leads to heating of the weak connectors used, the connectors in turn melt the plastic of the top hat, while submersed if fuel mind you, creating a fuel leak at the melted connector of the top hat. If you're lucky like me, your fuse blows and you investigate why instead of replacing it and continue to run the car. Continuing to run the car with this issue results in the car catching fire beneath the rear seat, above the fuel tank. A 30 amp circuit calls for 10 gauge wiring for short runs, Mercedes decided 16 gauge will do instead, along with connectors barely suitable to trigger a relay much less leave submerged in fuel while carrying 30 amps of current.

 

Warranty ran out in June of 2019, about 500 miles ago.

 

BTW, here's my fix for this:

1) drill out the top of the fuel sender and replace plastic fuel line fitting with brass fitting. There is no aftermarket sender, OEM is $500+ and you need an adapter cable on top of that.
2) replace the fuel filter with creative steel one or find an alternative.
3) bought an ebay/china replacement pump set for $130, going to use only the top hat, leaving OEM pumps and floats.
4) replace weak electrical connectors with bolted on/soldered on connectors.

 

1. You could also see if anyone here has a used filter from which you can pull the top. It would have to be the first or second-generation fuel filter/regulator/delivery-unit/tank-inner-module yada yada yada. FWIW I paid $418 for the third-generation filter/regulator I installed at the last major maintenance 14 months and 23,000 miles ago.
2. Febi Bilstein 39831. See: https://mbworld.org/forums/w211-amg/...p-replace.html
3. --
4. Replace the stock 40-amp relay with a 70-amp relay with larger power connectors. The larger relay runs cooler and removes a weak link in the circuit.

Useful information:
-The power wires from the fuse to the relay and then to the pumps are 4 mm square (falls between a 12 and 10 gauge AWG). That's a standard DIN size rated for 30 amps. At joint Z7/24, the single 4 mm square changes to dual 2.5 mm square wires (one wire per fuel pump) and rated ~20 amps.
-The wire from F82 (rear pre-fuse block) to the the fuse is 6 mm square.
-Power wire to the relay solenoid is 1.5 mm square. The other wire from the solenoid to the open collector in the SAM is only 0.5 mm square. Don't ask me why the engineer picked the different sizes.
-Yearly pull the 30-amp fuse and check the blades for corrosion; I pulled mine and the blades looked pretty bad. I have photos of the fuse in my post on E55 fuel pump relay and fuse maintenance.
-Last replacement each new pump measured at ~13 amps *each*. As the filter clogs, the amperage increases but the single relay generally melts before the fuse blows. 2006 model year went to dual relays to address this issue. I measure the amperage draw every oil change and can literally track the changes in amperage as the filter does its thing removing particulates.
-I also use carbon conductive paste on any of the bladed connections.
-Be sure to install a piece of adhesive backed foam ~1" square and 1/8" to 1/4" thick on the underside of the metal lid over the fuel pumps. That way, in case the wires overheat and the insulation melts/deteriorates (as seen in multiple photos) you reduce the risk of a dead short from the harness to the metal lid.

Take photos and let us know how it works out.

 

Up here in Canada we never got the warranty extension for the fuel issue, so it's great that they fixed free of charge. I've also heard of a E500 wagon that had the SBC pump replaced for free due to the buzzing noise and vibration complaint (we never got the SBC warranty either). Don't know why Mercedes decided to do that for free, but never hurts to ask. Or maybe MBUSA is more strict with out of warranty cases due to the fact that you guys had a warranty?

 

From the pic’s on eBay the plastic hat on those pumps looks thinner than OEM How does it compair in person?

Another option is to get a set of DavesmeanE’s billet hat’s. That is what I would have done. But I had already pulled the trigger on the OEM’s 😭

 

Does anybody know whether W211 E63s suffer from the same problem, or was it only E55? If they do, how can I get my dealer to replace it before it actually fails? If I say something like I smell gas would that work?

 

We did get the Sbc warranty in Canada. Or should I say we have it. Its 25 years. I got mine replaced on my 2005 E500. Now I have about 4 years for my E55 left. Hope it goes soon so it can be fixed for free

 

I believe it's all W211's. But you can have the dealer check. You would have to take the back seat off and pour a little gas on top of the fuel tank as that's how they usually diagnose it. If you just say you smell gas, they're probably just going to say no problem found and charge you for diagnosis.

 

That's great news Can you PM me some more info (so we don't derail/clog the thread)? I'm at the mileage where the original pump should be nearing the end of its life...

 

man, I read this thread a few days ago and though "glad mine doesn't have this issue".
Today I filled up and....fuel smell... ****!! I called the dealer and confirmed that I still have warranty till March 2021,

 

Just go to your local mercedes dealership. aif there is a problem with the pump they will replace it for free

 

Extended warranty on fuel pump and associated issues. Before I bought my E55 this summer, the dealer had replaced I believe the pump, tank, filter, etc under the extended warranty.

 

In these photos, 3 dots locked position, 5 dots unlocked position. I had to put the body in a vise and use a large strap wrench to rotate the upper portion. Be sure to depress the locking tab when starting to unlock; it will lock automatically when tightened. It took a bit of effort to rotate to the unlock position plus wiggling the top loose due to the rubber o-ring inside. You may want to apply some sort of lubricant when reassembling. Be advised Creative Steel advertises their filter as more efficient at capturing particles so it may need to be replaced prior to the factory-recommended 60,000 miles.